Cobalt House And 43 Bonhill Road, Bonhill Road, Dumbarton

Cobalt House and 43 Bonhill Road is a classical house built around 1820. It is two stories tall and features a symmetrical five-bay south front with a lower service wing extending to the north. The exterior is finished in polished ashlar.

The south elevation has a slightly advanced and pedimented central bay that includes a double pilastered doorpiece, a recessed panelled door with pilastered jambs, and a rectangular fanlight above. There is a tripartite window on the first floor above the door. The remaining bays have single windows that are corniced at the ground floor and feature corbelled cills. All windows are 12-pane sashes set within architraves. The building is accented with broad angle pilasters, an eaves course, a cornice, and a blocking course. The corniced end stacks and the shallow-pitched piended slate roof add to its classical appearance. The side elevation has two bays and includes a round-headed stair window in the advanced central bay on the north side.

Inside, most of the larger rooms have been subdivided, but some ceiling plasterwork remains, along with cast-iron stair balusters. The low two-storey wing has a central door on the east elevation, flanked by bipartite windows.

To the east, there are three square, polished ashlar, panelled and corniced gatepiers, accompanied by simple cast-iron gates.